1. Field of the Invention
The present invention relates to a linear sliding rail having a self-lubricating unit capable of adjusting a lubricant amount supplied therefrom. More particularly, the present invention relates to a self-lubricating unit which continuously adjusts the lubricant supplied therefrom at any time without the need of detaching a linear sliding body attached thereto so as to achieve the optimal efficiency and meet the requirements of a user.
2. Description of Related Art
In a mechanical processing platform, a linear sliding rail is generally utilized to carry and guide a sliding body which is used to position a processing tool or a to-be-processed object. Accordingly, how precise the to-be-processed object may be processed is directly dependent on how precise, wear-resistive and sensitive to heat of the shape of the sliding body and thus should be well designed by a designer of the art.
Referring to FIG. 1, a schematic diagram of a prior art sliding rail structure is shown therein. As shown, a sliding body is movably fitted on a sliding rail 130. At two sides of the sliding rail 130, bead slots 131 are disposed on which rolling beads (not shown) are disposed for contacting with the sliding body 100 so that the sliding body 100 may move precisely on the sliding rail 130. At two ends of the sliding body 100, an end cover 110 is disposed. At an outer side of the end cover 110, a lubricant removing piece 120 is disposed, on which a hole 121 is provided. The lubricant removing piece 120 is fixed to the end cover 110 through screws 122 each penetrating a threaded hole 111 of the end cover 110. The lubricant removing piece 120 is used to enhance lubricate sealing capability for the sliding body 100 and also remove redundant lubricate and screenings on the sliding body 100. Therefore, the performance of the lubricating system is critical to the linear sliding rail and thus the self-lubricating unit stays at the heart of research for the linear sliding rail. Generally, a self-lubricating capable lubricant storage unit is disposed within the sliding body and the sliding rail may be lubricated by the lubricate automatically released from the lubricant storage unit. As such, difficulty and error caused from an operator may be reduced. Currently, there are some lubricating mechanisms of such self-lubricating units set forth, which will be described below.
At a facet of the sliding body, a lubricating body made of a porous plastic material is mounted to cover the linear sliding rail, which may be seen in, for instance, U.S. Pat. Nos. 6,019,513 and 6,461,045. In the lubricating body, a lubricating medium is contained so as to directly lubricate the lubricate bead slot of the sliding rail.
A self-lubricating unit is amounted at the facet of the sliding body, which may be seen in, for instance, in U.S. Pat. Nos. 6,401,867, 6,155,717 and TW patents 572143. The self-lubricating unit has a lubricate-rich material which can be served as a lubricate container and a lubricant-containing device which is used to deliver the lubricant. When the lubricant-containing device is contacted with the sliding rail, the lubricant can be supplied to the bead slots.
A lubricant tank in which the lubricant is received is amounted at a facet of the sliding body. Such technology may be seen in, for instance, U.S. Pat. Nos. 6,123,457 and 6,257,766. The lubricant is delivered to bead slots through a lubricant-containing device which covers an opening of the lubricant tank.
A lubricant storage hole is formed on the sliding body, which may be seen, for example, in U.S. Pat. No. 6,250,804. The lubricant is drawn out from the lubricant storage hole by means of a cellulose containing material such as wool felt through capillarity and then onto the roll beads within the sliding body.
For the above mentioned linear self-lubricating units, all they provide the lubricant through the fine hole based on capillarity so that the linear sliding rail is lubricated. Since such designs may provide good performance in terms of lubricating of the sliding body, manual labor may be saved. However, the above and prior art lubricating designs may only supply a fixed amount of lubricant, i.e. the supplied amount of the lubricant has been set according to a specific lubricating task when the lubricating system is manufactured, it is impossible to change the supplied amount of the lubricant when the lubricating task is under the way. When the linear sliding rail is intended to have another working state, e.g. an increased lubricant amount is required when a larger load is added, the sliding body structure has to be detached so that the self-lubricating unit may be replaced or adjusted properly. For example, the lubricant supplying material has to be replaced so that the new lubricant supplying material may draw a different lubricant amount and thus provide a different lubricating effect. Finally, the sliding body has to be assembled to finish the following lubricating process.
Furthermore, a lubricating extent of the linear sliding rail structure having the self-lubricating unit may not be real time adjusted for a large load. The replacement task has to be conducted with the machine off the line, which wastes process time and reduces working efficiency. Moreover, the detachment and replacement requirements of the self-lubricating unit necessitate a different manufacturing method of the linear sliding rail as compared to the standard manufacturing process, leading to an increased cost and a difficult maintenance work.
In view of the shortcomings existing in the prior art self-lubricating units of the current linear sliding rail, the Inventor has made a continuous research and finally sets forth a linear sliding rail having a self-lubricating unit capable of adjusting a lubricant amount supplied therefrom without the need of modifying the current linear sliding rail structure.